Awake Surgery Research Articles

O conceito de área de Broca não existe em gliomas de baixo grau – uma série decasos

Introduction: Broca`s area is a region located in the left inferior frontal gyrus and is classically correlated to language. However, we observe preservation of speech function after tumor resection in this area. Awake surgery with direct brain stimulation is a reliable method to evaluate the functional role in this area. Objective: To evaluate the Broca´s area function. Methods: In a series of 69 patients with tumors in eloquent areas, 7 patients with tumors involving Broca´s area undergoing awake surgery with direct brain stimulation between 2007 and 2017 were retrospectively evaluated. Results: From 7 patients with Broca´s area stimulation, 5 did not show any alteration of speech. One patient, Portuguese native speaker, started to speak in English during the stimulation. The last patient diagnosed with glioblastoma already had a partial speech deficit, and showed a complete interruption of speech during the stimulation of Broca`s area. Conclusions: Broca`s area does not seem to be crucial for language function in patients with gliomas involving this area, particularly in lowgrade gliomas. The direct brain stimulation is a very useful tool to analyze the correlation between anatomy and brain function.

Brain tumor surgery guided by navigated transcranial magnetic stimulation mapping for arithmetic calculation.

The onco-functional balance represents the primary goal in neuro-oncology. The increasing use of navigated transcranial magnetic stimulation (nTMS) allows the noninvasive characterization of cortical functional anatomy, and its reliability for motor and language mapping has previously been validated. Calculation and arithmetic processing has not been studied with nTMS so far. In this study, the authors present their preliminary data concerning nTMS calculation. The authors designed a monocentric prospective study, adopting an internal protocol to use nTMS for preoperative planning, including arithmetic processing. When awake surgery was possible, according to the patients' conditions, nTMS points were used to guide direct cortical stimulation (DCS), i.e., the gold standard for cortical mapping. Navigated TMS-based tractography was used for surgical planning. Statistical analyses on the nTMS and DCS points were performed. From February 2021 to October 2023, 61 procedures for nTMS calculation mapping were performed. The clinical evaluation, including pre- and postoperative evaluations (3 months after surgery), demonstrated a good clinical outcome with preservation of arithmetic function and recovery (92.8% of patients). Between the awake and asleep surgery groups, the postoperative clinical results were comparable at the 3-month follow-up, with > 90% of the patients achieving improved calculation function. The surgical strategy adopted was aimed at sparing nTMS positive points in asleep procedures, whereas nTMS and DCS positive points were not removed in awake procedures. Overall, 62% of the positive points for calculation functions were exposed by craniotomy and 85% were spared during surgery. None of the patients developed nTMS-related seizures. Diffusion tensor imaging fiber tracking based on nTMS positive points for calculation was used. The white matter fiber tracts involved in calculation functions were the arcuate fasciculus (56%) and frontal aslant tract (22%). When nTMS and DCS points were compared in awake surgery (n = 10 patients), a sensitivity of 31.71%, specificity of 85.76%, positive predictive value of 22.41%, negative predictive value of 90.64%, and accuracy of approximately 69% were achieved. Based on the authors' preliminary data, nTMS can be an advantageous tool to study cognitive functions, aimed at minimizing neurological impairment. The postoperative clinical outcome for patients who underwent operation with nTMS was very good. Considering these results, nTMS has proved to be a feasible method to map cognitive areas including those for calculation functions. Further analyses are needed to validate these data. Finally, other cognitive functions (e.g., visuospatial) may be explored with nTMS.

Incidence, Associated Factors, and Behavioral Consequences of Intraoperative Awareness and Dreams During General Anesthesia Among Adult Patients: A Prospective Cohort Study.

Background The intraoperative awareness with recall phenomenon involves the memory of intraoperative events. The reported incidence is 0.001%. Awareness is rare intraoperatively but has profound implications. This research aimed to study intraoperative awareness and dream experiences in the Omani population undergoing general anesthesia. Methods This prospective cohort study involving 300 adult patients was conducted at a tertiary-level hospital between July and December 2021. Awareness was assessed in the post-anesthesia care unit and then at home on the seventh day and one month telephonically using a modified Brice questionnaire. The study's primary outcome was the incidence of IOA and dreams in adult Omani patients undergoing GA. The secondary outcome was identifying the factors associated with intraoperative awareness and dreams under GA. Results In this study, the incidence of awareness was 0.3%while 7.6% of patients reported intraoperative dreams. The patient who experienced IOA underwent an endoscopic retrograde cholangiopancreatography under GA with neuromuscular blockade and had a prolonged recovery. A total of 49.33% developed psychological effects postoperatively; anxiety, irritability, fear of surgery, change in memory, and repetitive nightmares were the most common ones. Because of the limited sample size, no factor associated significantly with these outcomes was found. Conclusion This study observed a higher incidence of intraoperative awareness and dreams. Awareness might be due to prolonged recovery and the use of neuromuscular blocking agents, but a focused study is required to confirm this finding. The incidence of intraoperative dreams and postoperative psychological effects of GA was also high. It may be worth exploring these findings with larger population-based research.

Comparison of the Safety and Efficacy of Remimazolam Besylate versus Dexmedetomidine for Patients Undergoing Fiberoptic Bronchoscopy: A Prospective, Randomized Controlled Trial.

Remimazolam besylate is a novel ultra-short-acting benzodiazepine that is rapidly hydrolyzed to zolpidem propionic acid by tissue lipases. We designed this study to compare the safety and efficacy of remimazolam besylate alfentanil versus dexmedetomidine-alfentanil for fiberoptic bronchoscopy (FB). One hundred and twenty patients undergoing FB into this prospective randomized controlled trial were divided into two groups. The anesthesia induction consisted of 6 mg/kg/h of remimazolam besylate in the RA group and 0.5 μg/kg of dexmedetomidine in the DA group. 1-2 mg/kg/h of remimazolam besylate or 0.2-0.7 µg/kg/h of dexmedetomidine were administered to maintain during FB. The lowest oxygen saturation, success rate of FB, hemodynamics, time metrics, bronchoscopy feasibility, drug dose requirements, patient and bronchoscopist satisfaction scores, occurrence of intraoperative awareness, number of patients willing to repeat FB with the same sedation regimen, and occurrence and severity of adverse events. The lowest oxygen saturation during the FB was significantly higher in the RA group (P = 0.001). Compared with the variables in the DA group, peripheral oxygen saturation, systolic blood pressure, and diastolic blood pressure were significantly lower at T2 and T3 in the RA group (P < 0.05). Heart rates were significantly higher from T2 to T4 in the DA group (P < 0.05). More patients experienced bradycardia in the DA group (P = 0.041). Compared with time metrics in the DA group, the induction time, fully-alert time, and recovery room-leaving time were all significantly shorter in the RA group (P < 0.05). The bronchoscopy feasibility scores in the RA group were significantly lower at T2, whereas they were lower at T3 in the DA group (P < 0.05). Remimazolam besylate is superior to dexmedetomidine when combined with alfentanil during FB, promoting faster patients' recovery, better operative conditions and respiratory stability with similar rates of occurrence and severity of adverse events.

Retroperitoneal Müllerian Cyst Found Incidentally During Total Laparoscopic Hysterectomy: Is There a Role for MRI in Pre-Operative Evaluation?

Retroperitoneal cysts of Müllerian origin are rare and often discovered incidentally during surgical procedures or imaging studies. We present a case of a retroperitoneal cyst found during a total laparoscopic hysterectomy performed for myoma removal. A 40-year-old female presented with symptomatic myomas and underwent pre-operative evaluation, including pelvic ultrasound, which revealed no abnormalities apart from the myomas. A cyst was incidentally discovered in the retroperitoneal space during a total laparoscopic hysterectomy procedure. The cyst was excised and sent for histological examination, which confirmed its Müllerian origin. Retroperitoneal cysts of Müllerian origin are rare findings during TLH. This case report highlights the importance of thorough pre-operative evaluation and imaging studies and the significance of intraoperative awareness in identifying incidental findings. Further research is warranted to determine the optimal diagnostic imaging strategies for such cysts.

Randomized Controlled Trial of Awake Transnasal Laser-Assisted Surgery for Benign Laryngeal Lesions.

To compare functional and cost-effectiveness of awake transnasal laser assisted-surgery versus microlaryngeal surgery for benign laryngeal lesions. This was a prospective non-inferiority randomized controlled trial conducted from May 2021 to December 2022 at two tertiary referral hospitals in Hong Kong. Patients were block-randomized to receive either awake transnasal laser-assisted surgery or microlaryngeal surgery, with post-operative follow-up in a multidisciplinary voice clinic for 1-year. Primary outcome was Voice Handicap Index (VHI-30). Secondary outcomes included operation time, complications, length of stay, peri-operative discomfort, recurrence, and medical costs. Sixty-one patients were randomized to either awake transnasal laser-assisted surgery (n = 30) and microlaryngeal surgery (n = 31). Both groups had comparable demographics and laryngeal pathologies. Both groups showed significant improvement of VHI-30 score over time and had comparable post-operative VHI-30. Awake transnasal laser-assisted surgery group had a significantly shorter length of stay (0.5 vs. 1 day) and less throat discomfort (2 vs. 4) compared to microlaryngeal surgery group. Intraoperative complications were more common in microlaryngeal surgery group (14.3% vs. 0%). Otherwise, both groups had similar operative time and recurrence rate. Cost-analysis showed a significantly lower hospital cost for awake transnasal laser-assisted surgery (USD 3090) compared to microlaryngeal surgery group (USD 5120). Awake transnasal laser-assisted surgery was safe, functionally non-inferior, as measured by VHI-30, to microlaryngeal surgery in managing benign laryngeal lesions, while superior to microlaryngeal surgery in peri-operative discomfort and medical costs. 2 Laryngoscope, 134:3732-3740, 2024.

Toward a systematic grading for the selection of patients to undergo awake surgery: identifying suitable predictor variables.

Awake craniotomy is the standard of care for treating language eloquent gliomas. However, depending on preoperative functionality, it is not feasible in each patient and selection criteria are highly heterogeneous. Thus, this study aimed to identify broadly applicable predictor variables allowing for a more systematic and objective patient selection. We performed post-hoc analyses of preoperative language status, patient and tumor characteristics including language eloquence of 96 glioma patients treated in a single neurosurgical center between 05/2018 and 01/2021. Multinomial logistic regression and stepwise variable selection were applied to identify significant predictors of awake surgery feasibility. Stepwise backward selection confirmed that a higher number of paraphasias, lower age, and high language eloquence level were suitable indicators for an awake surgery in our cohort. Subsequent descriptive and ROC-analyses indicated a cut-off at ≤54 years and a language eloquence level of at least 6 for awake surgeries, which require further validation. A high language eloquence, lower age, preexisting semantic and phonological aphasic symptoms have shown to be suitable predictors. The combination of these factors may act as a basis for a systematic and standardized grading of patients' suitability for an awake craniotomy which is easily integrable into the preoperative workflow across neurosurgical centers.

Influences of Propofol, Ciprofol and Remimazolam on Dreaming During Anesthesia for Gastrointestinal Endoscopy: A Randomized Double-Blind Parallel-Design Trial.

To compare the influences of propofol, ciprofol and remimazolam on dreaming during painless gastrointestinal endoscopy. This study was a single-center, prospective, parallel-design, double-blind, randomized clinical trial. Between May 2023 and October 2023, patients undergoing elective painless gastrointestinal endoscopy were recruited and randomly allocated into one of the three groups. Demographic data, intraoperative information, incidence of dreaming, insufficient anesthesia and intraoperative awareness, type of dream, patient satisfaction score, adverse events, and improvement of sleep quality were collected. The difference in incidence of dreaming among the three groups was not significant (33.33% vs 48.33% vs 41.67%, p=0.061). The number of patients with intraoperative hypotension in the propofol group was larger than that of the remimazolam group (32 vs 12, p=0.001). However, the cases of intraoperative hypotension between propofol group and ciprofol group or ciprofol group and remimazolam group were comparable (32 vs 22, p=0.122; 22 vs 12, p=0.064). The percentage of insufficient anesthesia between propofol group and remimazolam group was significant (13.33% vs 1.67%, p=0.001), while no statistical difference was detected between propofol group and remimazolam group or ciprofol group and remimazolam group (13.33% vs 5.00%, p=0.025; 5.00% vs 1.67%, p=0.150). The ability of propofol to improve sleep quality at 1st post-examination day was significantly better than that of remimazolam (86.21% vs 72.88%, p=0.015), while it was not significant between propofol group and ciprofol group or ciprofol group and remimazolam group (86.21% vs 80.36%, p=0.236; 72.88% vs. 72.88%, p=0.181). Incidence of intraoperative awareness, intraoperative hypoxia, type of dream, satisfaction score, adverse events during recovery, and sleep improvement on the 7th post-examination day was not significant among the groups. Anesthesia with propofol, ciprofol and remimazolam, respectively, for gastrointestinal endoscopy did not induce statistical difference in the incidence of dreaming, despite that all of them are more likely to induce pleasant dreams.

Don’t stop the block – Why all breast units should offer routine awake breast surgery

Don’t stop the block – Why all breast units should offer routine awake breast surgery

The effect of propofol-midazolam versus sevoflurane on bispectral index and eye position in pediatric cataract surgery: A randomized controlled study

ABSTRACT Background Cataract surgery is one of the infrequent ocular surgeries. The adequate ocular position with central alignment is the main prerequisite for good surgical technique. Propofol and sevoflurane are the common anesthetics drugs used during pediatric anesthesia. BIS monitor is one of the common intraoperative awareness monitors used. Aim To assess the efficacy of the bispectral index monitor in quantifying the depth of anesthesia and its correlation with ocular alignment during juvenile cataract surgery. Specifically, we will compare the use of sevoflurane anaesthesia with total intravenous anesthesia using a midazolam bolus and propofol infusion. Methods This study included 100 children scheduled for cataract surgery. The children were divided into two groups: group (S) included 50 children who were anesthetized using sevoflurane maintenance only and group (P) included 50 children who were anesthetized using continuous intravenous anesthesia (midazolam bolus plus propofol infusion) as maintenance after induction with sevoflurane anesthesia 8%. The bispectral index was recorded immediately after induction and after intubation and every 5 min later on until end of surgery. Results The eye position showed statistically significant central position among the propofol group with p value 0.02. An eye position-BIS value association was found statistically significant negative correlation in sevoflurane group while no statistically significant link was found in the propofol group. Conclusion Use of BIS monitor for making correlation between depth of anesthesia for prediction of ocular alignment was significant in sevoflurane group, but not in propofol group in pediatric patients and even with adequate depth of general anesthesia.

Functional and oncological outcomes after right hemisphere glioma resection in awake versus asleep patients: a systematic review and meta-analysis.

The right hemisphere has been underestimated by being considered as the non-dominant hemisphere. However, it is involved in many functions, including movement, language, cognition, and emotion. Therefore, because lesions on this side are usually not resected under awake mapping, there is a risk of unfavorable neurological outcomes. The goal of this study is to compare the functional and oncological outcomes of awake surgery (AwS) versus surgery under general anesthesia (GA) in supratentorial right-sided gliomas. A systematic review of the literature according to PRISMA guidelines was performed up to March 2023. Four databases were screened. Primary outcome to assess was return to work (RTW). Secondary outcomes included the rate of postoperative neurological deficit, postoperative Karnofsky Performance Status (KPS) score and the extent of resection (EOR). A total of 32 articles were included with 543 patients who underwent right hemisphere tumor resection under awake surgery and 294 under general anesthesia. There were no significant differences between groups regarding age, gender, handedness, perioperative KPS, tumor location or preoperative seizures. Preoperative and long-term postoperative neurological deficits were statistically lower after AwS (p = 0.03 and p < 0.01, respectively), even though no difference was found regarding early postoperative course (p = 0.32). A subsequent analysis regarding type of postoperative impairment was performed. Severe postoperative language deficits were not different (p = 0.74), but there were fewer long-term mild motor and high-order cognitive deficits (p < 0.05) in AwS group. A higher rate of RTW (p < 0.05) was documented after AwS. The EOR was similar in both groups. Glioma resection of the right hemisphere under awake mapping is a safer procedure with a better preservation of high-order cognitive functions and a higher rate of RTW than resection under general anesthesia, despite similar EOR.

Prevention of accidental awareness under general anaesthesia: A regional service evaluation.

The United Kingdom's Fifth National Audit Project investigated the incidence and causes of accidental awareness during general anaesthesia. Subsequently, guidelines produced by the Association of Anaesthetists of Great Britain and Ireland provide key recommendations to minimise awareness. These include using processed electroencephalogram for patients receiving total intravenous anaesthesia while paralysed and using audible low end-tidal anaesthetic concentration alarms. The Southcoast Perioperative Audit and Research Collaboration undertook a five-day regional service evaluation, assessing the measures in place to minimise awareness and conducting a practitioner survey. Eight hospitals participated with 382 theatre attendances were analysed. Processed electroencephalograph monitoring for patients receiving total intravenous anaesthesia with neuromuscular blockade has been widely adopted into regional practice, from 23% of cases in the Fifth National Audit Project, to 85% in this snapshot. During volatile anaesthesia, age-adjusted low end-tidal anaesthetic concentration alarms were used in 34% cases. The range was 0-97% at different hospitals, suggesting heterogeneity in practice. Seventy-six per cent of anaesthetists rarely alter the default anaesthetic machine alarm settings. Therefore, instigating default low end-tidal anaesthetic concentration alarms could improve compliance with guidelines and reduce the risk of awareness for patients.

Comparison of the Effects of Inhalational Anesthesia with Sevoflurane and Total Intravenous Anesthesia in Open Heart Surgery

Background: The primary objective of this study was to compare sevoflurane inhalation anesthesia with total intravenous anesthesia (TIVA) in terms of its effectiveness in maintaining adequate depth of anesthesia during all open heart surgery procedures, including cardiopulmonary bypass. The study's secondary objective was to compare sevoflurane inhalation anesthesia with TIVA regarding the impact on the time of tracheal extubation and the incidence of postoperative acute kidney injury during open heart surgeries. Methods: A total of 58 patients undergoing open heart surgery were included, with 30 receiving sevoflurane inhalation anesthesia and 28 receiving TIVA. Demographic characteristics, intraoperative parameters, and postoperative outcomes were recorded and analyzed. Statistical analysis revealed no significant differences in Bispectral Index (BIS) monitor values, mean arterial pressure, body temperature, or other intraoperative parameters between the two groups. Notably, the time to tracheal extubation was significantly shorter in the Sevoflurane group compared to the TIVA group, although both groups exhibited similar rates of postoperative acute kidney injury (AKI). Results: None of the patients had complaints of intraoperative awareness. The mean arterial pressure, body temperature, and bispectral index values during and before cardiopulmonary bypass were similar between the groups. Postoperative variables such as intensive care unit stay duration, incidence of acute kidney injury, and immediate and 24-hour post-extubation visual analog scale values were similar between the groups. The tracheal extubation time was found to be statistically shorter in the sevoflurane group. Conclusion: We believe that sevoflurane inhalation anesthesia can achieve adequate depth of anesthesia during the intraoperative period in open heart surgery without increasing the rate of postoperative complications.

Awake surgery in neurooncology. Part 2. Functional intraoperative mapping

Awake surgery is usually used to save patient’s speech. Various tests are applied for this purpose, whish selection depends on tumor location. In multilingual patients verbal centers usually have different position. Location of each of them is necessary to keep patient’s communication capabilities after operation.To study vision, tests with presentations of color points or pictures on the screen divided on 4 parts are used. Such testing allows to estimate vision and speech simultaneously.Mapping of motor area in awake patients allows to evaluate this function more comprehensively including motion planning, proprioceptive control and balance. Stimulation of sensory area in awake patients gives opportunity to differ various types of sensitivity.Mapping and keeping of cognitive functions, memory, attention and ability of calculation increases chance to save professional skills and quality of life after operation.

Perioperative Neurocognitive Function in Glioma Surgery.

This review provides a concise overview of the recent literature regarding preoperative and postoperative neurocognitive functioning (NCF) in patients with glioma. Brief discussion also covers contemporary intraoperative brain mapping work, with a focus on potential influence of mapping upon NCF outcomes following awake surgery. Most patients with glioma exhibit preoperative NCF impairment, with severity varying by germ line and tumoral genetics, tumor grade, and lesion location, among other characteristics. Literature regarding postoperative NCF changes is mixed, though numerous studies indicate a majority of patients exhibit immediate and short-term worsening. This is often followed by recovery over several months; however, a substantial portion of patients harbor persisting declines. Decline appears related to surgically-induced structural and functional brain alterations, both local and distal to the tumor and resection cavity. Importantly, NCF decline may be mitigated to some extent by intraoperative brain mapping, including mapping of both language-mediated and nonverbal functions. Research regarding perioperative NCF in patients with glioma has flourished over recent years. While this has increased our understanding of contributors to NCF and risk of decline associated with surgical intervention, more work is needed to better preserve NCF throughout the disease course.

Improvement of diffusion tensor imaging-based tractography by free-water correction in nonedematous gliomas: assessment with brain mapping.

The free-water correction algorithm (Freewater Estimator Using Interpolated Initialization [FERNET]) can be applied to standard diffusion tensor imaging (DTI) tractography to improve visualization of subcortical bundles in the peritumoral area of highly edematous brain tumors. Interest in its use for presurgical planning in purely infiltrative gliomas without peritumoral edema has never been evaluated. Using subcortical maps obtained with direct electrostimulation (DES) in awake surgery as a reference standard, the authors sought to 1) assess the accuracy of preoperative DTI-based tractography with FERNET in a series of nonedematous glioma patients, and 2) determine its potential usefulness in presurgical planning. Based on DES-induced functional disturbances and tumor topography, the authors retrospectively reconstructed the putatively stimulated bundles and the peritumoral tracts of interest (various associative and projection pathways) of 12 patients. The tractography data obtained with and without FERNET were compared. The authors identified 21 putative tracts from 24 stimulation sites and reconstituted 49 tracts of interest. The number of streamlines of the putative tracts crossing the DES area was 26.8% higher (96.04 vs 75.75, p = 0.016) and their volume 20.4% higher (13.99 cm3 vs 11.62 cm3, p < 0.0001) with FERNET than with standard DTI. Additionally, the volume of the tracts of interest was 22.1% higher (9.69 cm3 vs 7.93 cm3, p < 0.0001). Free-water correction significantly increased the anatomical plausibility of the stimulated fascicles and the volume of tracts of interest in the peritumoral area of purely infiltrative nonedematous gliomas. Because of the functional importance of the peritumoral zone, applying FERNET to DTI could have potential implications on surgical planning and the safety of glioma resection.

207 Intraoperative Functional Re-mapping Unveils Evolving Patterns of Cortical Plasticity

INTRODUCTION: Diffuse low-grade gliomas (DLGG) induce a compensatory modulation of the anatomo-functional architecture, making this kind of brain tumours an ideal lesion model to study the dynamics of neuroplasticity. Direct electrostimulation (DES) mapping is a well-tried procedure used during awake resection surgeries to spare cortical epicenters which are critical for a range of functions. Because DLGG is a chronic disease, it inevitably relapses years after the initial surgery, and thus requires a second surgery to reduce tumour volume again. METHODS: We capitalized on a series of 101 DLGG patients who benefited from two DES-guided neurosurgeries usually spaced several years apart, resulting in a DES dataset of 2082 cortical sites. We used a multi-step approach to generate probabilistic neuroplasticity maps that reflected the dynamic rearrangements of cortical mappings from one surgery to another, both at the population and individual-level. RESULTS: Voxel-wise neuroplasticity maps revealed regions with a high potential of evolving reorganizations, including the supplementary motor area (SMA), the dorsolateral prefrontal cortex (dlPFC), the anterior ventral premotor cortex (vPMC) and the middle superior temporal gyrus (STG). Parcel-wise neuroplasticity maps confirmed this potential for the dlPFC, the anterior and the ventral precentral gyrus. A series of clustering analyses revealed a topological migration of clusters, especially within the left dlPFC and STG (language sites); the left vPMC (speech arrest/dysarthria sites) and the right SMA (negative motor response sites). At the individual level, these dynamic changes were confirmed for the dlPFC (bilateral), the left vPMC and the anterior left STG (threshold free cluster enhancement, 5000 permutations, family-wise-error-corrected). CONCLUSIONS: Our results provide a critical insight into the dynamic potential of DLGG-induced continuing rearrangements of the cerebral cortex, with considerable implications for re-operations.

Evaluating the Accuracy of Patient State Index for Measuring Anaesthetic Depth in Patients Undergoing Propofol-Sevoflurane Anaesthesia

Abstract Processed electroencephalographic indices such as the Patient State Index (PSi) have been proposed as a method of monitoring the depth of general anaesthesia. However, in order to establish the validity of PSi, it is necessary to compare its accuracy to other techniques, such as the isolated forearm technique (IFT). 30 ASA (American Society of Anaesthesiologists classification) I–III patients were administered standard propofol-sevoflurane anaesthesia with PSi monitoring. Before each dose of muscle relaxant, the forearm contralateral to the intravenous cannula was isolated for 30 minutes. PSi, hand movements, and exhaled sevoflurane concentrations were recorded during the induction of anaesthesia, intubation, throughout the surgical procedure, prior to extubation, and patients’ responses to commands were classified as positive or negative. The Brice questionnaire was used to assess intraoperative awareness after the patient regained consciousness. All patients completed the study without memory of the surgery or IFT commands, 53.3% of patients showed a response to IFT commands during intubation. PSi values ranged around 26 (23.5; 30) in IFT non-responders and 33.5 (26; 42) in responders (p = 0.15). The best cut-off value for PSi to predict IFT response was 55, with a sensitivity of 60% and specificity of 85.2%, which led to the conclusion that PSi is not a fully reliable tool for monitoring the depth of anaesthesia.

Are there beneficial effects to hybrid anesthesia*?

As the COVID-19 pandemic increased the use of propofol in the intensive care unit for the management of respiratory sequelae and supply had become a major issue. Indeed, most hospitals in Japan were forced to use propofol only for induction of anesthesia with inhalational maintenance. Large amounts of propofol remain in the syringe which exacerbates the problems by increased waste. I propose that use of low dose propofol in combination with a low concentration inhaled anesthetic as an alternative and call this hybrid anesthesia. Several advantages of hybrid anesthesia are evident in the literature. Volatile anesthesia has several disadvantages such as cancer progression, emergence agitation, marked reduction in motor evoked potentials (MEP), laryngospasm with desflurane and postoperative nausea and vomiting (PONV). Volatile anesthesia exerts some beneficial actions such as myocardial protection and fast emergence with desflurane. In contrast, total intravenous anesthesia (TIVA) provides better survival in patients undergoing radical cancer surgery, reduction in emergence agitation, laryngospasm, PONV and better MEP trace Intraoperative awareness occurs more often during TIVA. When intravenous and volatile anesthesia are combined (hybrid anesthesia), the disadvantages of both methods may be offset by clear advantages. Thus, hybrid anesthesia may, therefore, be a viable anesthetic choice.

Motor or non-motor speech interference? A multimodal fMRI and direct cortical stimulation mapping study

We retrospectively analyzed data from 15 patients, with a normal pre-operative cognitive performance, undergoing awake surgery for left fronto-temporal low-grade glioma. We combined a pre-surgical measure (fMRI maps of motor- and language-related centers) with intra-surgical measures (MNI-registered cortical sites data obtained during intra-operative direct electrical stimulation, DES, while they performed the two most common language tasks: number counting and picture naming).Selective DES effects along the precentral gyrus/inferior frontal gyrus (and/or the connected speech articulation network) were obtained. DES of the precentral gyrus evoked the motor speech arrest, i.e., anarthria (with apparent mentalis muscle movements). We calculated the number of shared voxels between the lip-tongue and overt counting related- and silent naming-related fMRI maps and the Volumes of Interest (VOIs) obtained by merging together the MNI sites at which a given speech disturbance was observed, normalized on their mean the values (i.e., Z score). Both tongue- and lips-related movements fMRI maps maximally overlapped (Z = 1.05 and Z = 0.94 for lips and tongue vs. 0.16 and −1.003 for counting and naming) with the motor speech arrest seed. DES of the inferior frontal gyrus, pars opercularis and the rolandic operculum induced speech arrest proper (without apparent mentalis muscle movements). This area maximally overlapped with overt counting-related fMRI map (Z = −0.11 and Z = 0.09 for lips and tongue vs. 0.9 and 0.0006 for counting and naming). Interestingly, our fMRI maps indicated reduced Broca's area activity during silent speech compared to overt speech. Lastly, DES of the inferior frontal gyrus, pars opercularis and triangularis evoked variations of the output, i.e., dysarthria, a motor speech disorder occurring when patients cannot control the muscles used to produce articulated sounds (phonemes). Silent object naming-related fMRI map maximally overlapped (Z = −0.93 and Z = −1.04 for lips and tongue vs. −1.07 and 0.99 for counting and naming) with this seed.Speech disturbances evoked by DES may be thought of as selective interferences with specific recruitment of left inferior frontal gyrus and precentral cortex which are differentiable in terms of the specific interference induced.